Bald eagles, as well as other wildlife, have suffered from a mysterious neurodegenerative disease in the southern United States since the 1990s. New research by Martin Luther University Hell-Wittenberg (MLU) in Germany and the University of Georgia in the USA identifies the causes of these deaths: toxins produced by cyanobacteria that grow on invasive aquatic plants. The problem is potentially exacerbated by the herbicides used to control these plants. The results were published in Science.
In 1994, U.S. Bald eagles died in large numbers in the state of Arkansas. The animals were losing control of their bodies, and holes had developed in their brains. A previously unknown neurodegenerative disease, called vascular myelin athyp (T (VM)), was identified, says Timo Niedermeyer, a professor at MLU’s Institute of Pharmacy.
Later, American researchers discovered that not only eagles were affected, but also their vegetarian prey. Scientists have found an association with the invasive aquatic plant (Hydrala verticileta) which grows in freshwater ponds in the affected areas. However, there were still some ponds with aquatic plants where the disease was not appearing. In 2005, Susan B., a professor of forestry, forestry and natural resources at the University of Georgia’s Vernal School. Wilde identified a previously unknown cyanobacterium on the leaves of Hydrala verticileta, which was found to be the cause of the disease. It turns out that vacuolar myeloma occurs only in places where cyanobacteria colonize invasive plants. She calls the bacterium “eagle killer or grows on hydrala”: Atok thnos hydrilicola.
Cyanobacterium a. Bacterial colonies of hydraulicola are invasive aquatic plants. Grows on the leaves of Verticileta. Credit: Susan Wilde
“I stumbled upon a press release issued by the University of Georgia and I was mesmerized by these findings, as I have worked with cyanobacteria for years.” Samples were sent to him, bacteria were cultured in the laboratory and he was sent to the U.S. for further testing. But tests came back negative: laboratory bacteria do not inspire the disease. “It’s not just the birds that go crazy, we do. We want to estimate this, “says Niedermeyer. Once again, he sent them colonized leaves. Molecule.He discovered a new substance that occurs only on leaves where cyanobacteria grow, but it is not produced in plant bacteria.
Their investigation of the chemical composition of different molecules showed that they contained five bromine atoms. “The design is really spectacular,” says Brainlinger. Properties are unusual for molecules formed by bacteria. And provide an explanation of why they do not produce toxins in laboratory conditions. Standard culture media in which cyanobacteria grow do not contain bromide. “Then we added bromide to our lab culture, and – the bacteria started making toxins,” says Brainlinger. Wilde and his colleagues tested the isolation molecule in birds, and finally, after nearly a decade of research in Wilde and Niedermeyer labs, they had evidence: the molecule triggers VM. According to the name of the bacterium, the researchers called their discovery et talkath on nootoxin, “the poison that kills eagles.” “Finally, we not only caught the killer, but also identified the weapon that the bacteria used to kill the eagle,” says Wilde.
Bald eagle flying.
A research team participating in the study of the Czech Academy of Sciences also found its departments. DNA Contains genetic information for the synthesis of new molecules. Why cyanobacteria produce toxins on aquatic plants in the first place, however, remains to be studied. A herbicide VM used to combat invasive aquatic plants. May play a decisive role in the phenomenon: it contains bromide and therefore can stimulate the production of toxins.
Neurological disease has not yet occurred in Europe, and no evidence of a toxic cyanobacterium has been found.
Reference: “Hunting an Eagle Killer: A Cyanobacterial Neurotoxin Causes Vascular Myelinopathy” Stefan Brainlinger, Tabita J. Phillips, Bridget Ann. Haram, Jain Mare, Jose A. Martinez Yerena, Pavel Hrozek, Roman Sobotka, W. Pithu Henderson Schmidter, Susan M. Williams, James d. Luddardel, h. Dayton Wilde, Wesley Garin, Andreja Kust, John W. Washington Washington, Christophe Wagner, Benedict Gear, Manuel LeBlanc, Ha He Ik Enke, Timo HJ Niedermeier and Susan B. Wilde, March 26, 2021. Science.
DOI: 10.1126 / science.x9050
The research was commissioned by Dutsch Forcechangsminschaft (German Research Foundation, DFG), Czech Science Foundation GA? R., U.S. Department of Homeland Security, U.S. Fish and Wildlife Service, Florida Fish and Wildlife Conservation Commission, Gulf States Marine Fisheries Commission, National Institute of Food and Agriculture McIntyre-Stencis Capacity Grant, and American Eagle Foundation.
